Girls and guys start sweating more in their early teens.
When this happens you need to pay attention to hygiene, taking a shower every day and changing cloths regularly. You also should use a deodorant. Fresh sweat is normally no problem, but old sweat smells bad.
Sweating poses no problem for most girls and guys. But with some it is so excessive that it leads to embarrassment. The wet shirt, clammy hands and wet socks may cause the person to avoid interacting socially. See: hyperhydrosis.
The most common places to sweat are the armpits, the hands and the feet. When puberty starts you normally sweat more than later on.

What to do if you sweat a lot?